package factory import ( "net/http" "net/http/httputil" "net/url" "strings" ) // newSingleHostReverseProxyWithHostHeader is based on NewSingleHostReverseProxy // from golang.org/src/net/http/httputil/reverseproxy.go and merely sets the Host // HTTP header, which NewSingleHostReverseProxy deliberately preserves. func newSingleHostReverseProxyWithHostHeader(target *url.URL) *httputil.ReverseProxy { targetQuery := target.RawQuery director := func(req *http.Request) { req.URL.Scheme = target.Scheme req.URL.Host = target.Host req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path) req.Host = req.URL.Host if targetQuery == "" || req.URL.RawQuery == "" { req.URL.RawQuery = targetQuery + req.URL.RawQuery } else { req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery } if _, ok := req.Header["User-Agent"]; !ok { // explicitly disable User-Agent so it's not set to default value req.Header.Set("User-Agent", "") } } return &httputil.ReverseProxy{Director: director} } // singleJoiningSlash from golang.org/src/net/http/httputil/reverseproxy.go // included here for use in NewSingleHostReverseProxyWithHostHeader // because its used in NewSingleHostReverseProxy from golang.org/src/net/http/httputil/reverseproxy.go func singleJoiningSlash(a, b string) string { aslash := strings.HasSuffix(a, "/") bslash := strings.HasPrefix(b, "/") switch { case aslash && bslash: return a + b[1:] case !aslash && !bslash: return a + "/" + b } return a + b }